Soft Smart Garments for Lower Limb Joint Position Analysis

Sensors (Basel). 2017 Oct 12;17(10):2314. doi: 10.3390/s17102314.


Revealing human movement requires lightweight, flexible systems capable of detecting mechanical parameters (like strain and pressure) while being worn comfortably by the user, and not interfering with his/her activity. In this work we address such multifaceted challenge with the development of smart garments for lower limb motion detection, like a textile kneepad and anklet in which soft sensors and readout electronics are embedded for retrieving movement of the specific joint. Stretchable capacitive sensors with a three-electrode configuration are built combining conductive textiles and elastomeric layers, and distributed around knee and ankle. Results show an excellent behavior in the ~30% strain range, hence the correlation between sensors' responses and the optically tracked Euler angles is allowed for basic lower limb movements. Bending during knee flexion/extension is detected, and it is discriminated from any external contact by implementing in real time a low computational algorithm. The smart anklet is designed to address joint motion detection in and off the sagittal plane. Ankle dorsi/plantar flexion, adduction/abduction, and rotation are retrieved. Both knee and ankle smart garments show a high accuracy in movement detection, with a RMSE less than 4° in the worst case.

Keywords: bending; capacitive sensor; exoskeleton; human motion monitoring; soft tactile sensor; strain sensor; textile; wearable system.

MeSH terms

  • Ankle Joint / physiology*
  • Biosensing Techniques / instrumentation*
  • Biosensing Techniques / methods*
  • Female
  • Humans
  • Knee Joint / physiology*
  • Male
  • Monitoring, Ambulatory / instrumentation*
  • Monitoring, Ambulatory / methods*
  • Movement
  • Range of Motion, Articular
  • Textiles